Photographic developing apparatus



April 30,1935. B, J. HALL 1,999,965

PHOTOGRAPHIC DEVELOPTNG APPARATUS Filed June 1, 1933 -latented A r. 30,1955 1 1,399,965

UNITED STATES PATENT OFFICE PHOTOGR-APHIC DEVELOPING APPARATUS BenjaminJames Hall, Westminster, England Application June 1, 1933, Serial No.673,897

In Great Britain June 17, 1932 a Claims. ((1 95- 94) This inventionrelates to photographic ap n alternative form of the heating mvans usedin ratus in which the development of photograplic prints is carried outby exposure to a gaseous Fig. 5 is a sectional diagrammatic view of avapour or gas impregnated atmosphere, the further modification of theinvention; I 5 prints being exposed to the action of the vapour g- 6 i aSec a diagrammatic w Of a 5 by carrying them between or upon fabricbands, Purifying Chamber d W y n on; a d fabric covered drums or othersuitable surfaces 7 is a Sectional diagrammatic View of and whereas ithas been the custom to accelerate d fi a the Purifying Chamber 0! 6. theformation of gaseous vapours by applying n e pp a s Shown y 1 I p y tWO10 heat to the volatile liquid or liquids and further r c band in actSuitably mounted m to free the photographic ,prints from clinging in thechamber B. The contiguous surfaces of vapours byallowing them to fallinto an airing the bands are supported by solid or perforated chamberfrom which th vapour re extr ct d plates D, D the surfaces of whichplates, curved by ventilation, I have discovered that the ac- 0r fl asrequired, are p at t e desired tem- 1;, celeration of volatilization canbe more empelatllre y the heating elements y hOt l5 ciently performed byintroducing the volatile water circulation or other convenient method.liquid or liquids into the chamber at a norm l The volatile liquidmay-be applied to one or both temperature and by heating the surfaceswhere bands, in any position and y y means inwhich development is totake place, in particular mainit can be most conveniently absorbed, andprefertaining such surfaces as it is desirable to keep ab y y 11 P p p prunning the full free from the moisture of condensation, at 9. Width fthe, band. higher temperature than any other part of the The printenters the apparatus mll the apparatus. By so doing the prints passthrough slit b and is discharged through the slit 12 prothe apparatus ina comparatively dry condition vided in the Chamber B for the D D andthere is no disturbance caused by the con- At Fig. 2 I h Showndiagrammatically a 25 densation of moisture upon the parts of themaapparatus in which I employ a Single fabric chine with which theprints come in contact. band A in C n t w h a solid r' p rf rated Bythis means the quality of the product is immetal plate D, the surface ofwhich plate, curved proved, considerable saving in the use of volatileor flat as required, is kept at the desired tempera- I liquid iseffected and the discharge of fumes ture by the heating elements 0 y hotWater diminished. circulation or other convenient heating method. Tofree the prints from clinging vapours, I A suppl nta y plate D1 andheaters ay provideapur'ifying chamber into which the prints beintroduced above the band A if desired. pass between a heated surfaceand an absorbent The p t enters the apparatus at and 1S 1 surface. Thesesurfaces. may be in direct contact discharged at b 35 or separatedslightly one from the other-they In the pp u Shown diagrammatically a.may be stationary or one or both may have mo- Fig. 3 I employ anon-absorbent band A 111 tion imparted tothem. tact with a curved orflat perforated plate or In cases where it is not convenient to use aven- S D forming One Side Of a chamber H in 40 fllating l xh t fan orany like m of which the volatile liquid enters and is vaporizeddischarging fume from t gppamtus, I provide by heater h The undersidesurface of the plate a water tank, tanks, spray or sprays or other D isheat d by the heating elements E, suitably means of condensation withinth 011 positioned to obtain the requisite degree of 8 casingtemperature. Or the perforated surface or grid which encloses theapparatus; 45 The invention is illustrated on the accompany- 3 3 2:3 f ig z gg g fiz g gi mg drawing in which enters thei aratus at b anddischarged Fig. 1 is a sectional diagrammatic view of one at pp form ormy invention; At Fig. 5 I have shown a form of apparatus in 2 15 asectional diagrammatic View of an which I employ a fabric covered drum Jrevolv- 50 alternative m t e inventim discmsed by ing in contact with asolid or pzrforated curved 8. metal plate D, the surface of which plateis kept is 8 Sectional diag ammatic view of a at the desired temperatureby heaters E, by hot a modification of my invention; water circulationor other convenient means. Fig. 4 is a sectional diagrammatic view of anThe liquid to be volatilized is conveyed to the fabric in any convenientway, by preference through the hollow spindle J of the drum J.

The mouth of the casing B in which the drum revolves is closed at K withthe exception of two full width slots k k for feeding and discharge,arranged at any desired distance from each other. The upper horizontalwall of the slot k is perfora-ted at k to allow the escape of vapours tothe outer casing B, and both walls of the slots is, k are heated by theheating elements e to prevent condensation.

To free the prints issuing from the developing apparatus from clingingvapours I may provide a purifying chamber, such purifying chamber, whichis intended for use in connection with any of the foregoing developingapparatus, being placed at the slot through which the print issues fromthe developing apparatus.

The purifying chamber, illustrated diagrammatically at Fig. 6 comprisesa casing B in whichan absorbent endless band A, moving round rollers ais arranged, a water tank L or air cooled chamber being provided in thebase of the cas ing B. The upper wall of the slot through which theprint'travels on issuing from the developing apparatus is formed by theplate N, such plate N being warmed by the heaters E, or by hot watercirculation or by any other suitable method. Or instead of employing theplate N in conjunction with the moving band A, I may employ twotravelling bands, the upper one of which is heated and the lower cooled,or vice versa.

At Fig. 7 I have shown a further modification of the purifying chamber.In this case instead of a moving absorbent band I may provide a fixedabsorbent surface P, between which surface and the warmed plate N theprint is caused to travel.

What I claim as my invention and desire to secure by Letters Patent is:-

1. An apparatus for the development of light sensitive sheet materialcomprising a casing having end, side, bottom and top walls, an entranceslot for sensitized sheet material in one side wall, an exit slot in theopposite wall and aligned with said first slot, spaced and parallelplates within said casing and defining a narrow passage therein betweensaid slots, separate heating means for each plate and adjacent thereto,an endless and absorbent conveyor in the upper portion of said casingand extending around the upper plate, a second endless absorbentconveyor in the lower portion of said casing and extending around thelower plate and so arranged as to contact with said first conveyorbetween said plates, separate means for introducing a volatiledeveloping liquid to each of said conveyors, and said heating meansbeing adapted to heat said plates and also to accelerate thevolatilization of said liquid.

2. An apparatus for the development of light sensitive sheet material.comprising a casing having end, side, bottom. and top walls, an entranceslot for said sheet material in one side wall, an exit slot in theopposite side wall and aligned with said first slot, spaced and parallelplates within said casing and defining a narrow passage therein betweensaid slots, endless and absorbent conveying means within said casing forconveying said maerial through said casing between said plates, meansfor introducing a volatile developing liquid to said conveying means,separate means for heating each of said plates and adjacent thereto,said last named means also serving to aid in the volatilization of saidliquid.

3. An apparatus for the development of light sensitive sheet material,comprising a casing, entrance and exit slots in said casing, a narrowpassage having top and bottom walls connecting said slots, endless andabsorbent conveying means within said casing for conveying said sheetmaterial through said passage, separate means for heating both the topand the bottom walls of said passage throughout their length, means forintroducing a volatile developing liquid to said conveying means, andsaid heating means also serving to accelerate the volatilization of saidliquid. l

4. An apparatus for the development of light sensitive sheet material,comprising a casing having side, end, bottom, and top walls, an entranceslot for sensitized sheet material in one side wall, an exit slot in theopposite side wall and aligned with said first slot, spaced and parallelplates within said casing and defining a narrow passage therein betweensaid slots, separate means for heating each plate throughout its length,an endless and absorbent conveyor in the upper portion of said casingand extending around the upper plate, means for introducing a volatiledeveloping liquid to said conveyor, and said heating means also servingto accelerate the volatilization of said liquid.

5. An apparatus for the development of light sensitive sheet material,comprising a casing having side, end, bottom, and top walls, spacedentrance and exit slots in one of said side walls, narrow passagesextending inwardly of said casing from said slots and terminating onopposite sides of a cylindrical chamber, an absorbent conveying cylinderrotatably mounted in said chamber,

means for introducing a volatile developing liquid to said cylinder, andseparate means for heating the top, and bottom walls of said passagesthroughout their length and means for heating the defining wall of saidchamber.

BENJAMIN JAMES HALL.

